Animation nodes - effector pushes and attracts with falloff on multiple objects
Welcome to StackExchange. This is very easy to do :)

Step-1: Put all the objects into a separate collection. Then, select all the objects and open the N-panel, click the option From Current Transforms under AN-tab. It will store the initial transforms of all the objects,


Step-2: Add the Collection Info node and select the collection in which you stored the objects (in Step-1). Then connect objects to the Object ID Key node
and in the search option select the Initial Transforms option,
  

Step-3: Then add an empty (I have renamed it as Effector). To move objects away from the Effector, we have to calculate the directions which are pointing toward the Effector (empty) from the objects' location. We can do that by subtracting the Effector's location from the locations of the objects. For further control, I have added another Vertex Math node (with Multiply mode) to restrict the motion of the objects in XY-plane by making Z = 0,
  

Step-4: Next, add the Offset Matrix node to offset the initial locations of the objects along the directions which we have calculated in Step-3, and also you can offset the rotations as you like,


Step-5: Final step is, add the Object Controller Falloff node to control falloff of Offset Matrix node, adjust of falloff node as you like,

By the way you can also combine the different falloffs.

Blend File: